A vehicle's periphery contains blind spots that cannot be seen from a driver's position, and it is thus necessary for drivers to pay careful attention to the vehicle's periphery when driving the vehicle. Many drivers feel they are unskilled at parking vehicles in general, and thus experience significant emotional stress particularly when backing a vehicle into a parking spot. In light of this, techniques that monitor a vehicle's periphery for obstacles have been used for some time (for example, see Patent Documents 1 and 2).
Patent Document 1 discloses an obstacle alert device for a vehicle, configured of a laterally-moving obstacle detection means, a lateral movement direction detection means, and a lateral movement information presenting means. The laterally-moving obstacle detection means detects an obstacle, in front of the vehicle, moving in a direction that crosses the direction in which the vehicle is moving. The lateral movement direction detection means detects the direction of the lateral movement of the obstacle detected by the laterally-moving obstacle detection means. The lateral movement information presenting means presents, to a driver, information regarding the direction of the lateral movement of the obstacle detected by the lateral movement direction detection means. Here, the lateral movement information presenting means displays an arrow indicating the direction of the lateral movement detected by the lateral movement direction detection means in a display unit.
Patent Document 2 discloses a vehicle periphery monitoring device configured of an imaging means, an obstacle detecting means, and a display means. The imaging means captures an image of the vehicle's periphery, including part of the vehicle itself. The obstacle detecting means detects an obstacle located in the vehicle's periphery and calculates a distance between the detected obstacle and the vehicle. The display means displays the image captured by the imaging means and an obstacle display image indicating the distance calculated by the obstacle detecting means in a single screen.